WASHINGTON —
Leaders from around the world are condemning North Korea's latest nuclear test.

U.N. Secretary General Ban Ki-moon described the move as "deeply destabilizing." He said it is a "clear and grave violation" of sanctions banning Pyongyang from nuclear and missile tests.

U.S. President Barack Obama called the test "highly provocative." He said in a statement it undermines regional stability and will not make North Korea safer. He called for "swift and credible" international action in response.

"North Korea has announced their nuclear test succeeded. I think [it] means a big threat, not only to Japan, but also to the East Asia region, as a whole," he said. "North Korea has also managed to develop an improved version of the “Taepodong 2” - a long-range ballistic missile, last December. Therefore, this nuclear threat is not only a concern for Japan, but also the world."

The location of the nuclear test site in North Korea.

In South Korea, President-elect Park Geun-hye, meeting with President Lee Myung-bak, said the test does nothing to help North Korea's position in the world.

"I think it only made North Korea turn [the] international society into North Korea's enemy and made itself isolated," she said.

Speaking from South Africa, Russian Foreign Minister Sergei Lavrov condemned the test, but cautioned against a military overreaction in the region.

"We firmly count that today's action by Pyongyang, which deserves condemnation, will not be used as a pretext for an increasing of military activity in the area of the Korean peninsula,'' he said.

Speaking in Paris, British Foreign Minister William Hague discussed what the appropriate international reaction to the test should be.

"There is additional pressure that can be placed on North Korea, and additional sanctions that can be put in place that, of course, have the most effect," he said."That they have the strong support of China, of course a key nation in this regard and a permanent member of the Security Council, and China agreed that there could be significant action if this happened. So, we will now look to them to discuss that with them.''

NATO said the nuclear test, combined with North Korea's December missile launch, poses a "grave threat to international peace, security and stability."

China, North Korea's main ally, expressed what it called "firm opposition" to the test. Beijing's foreign ministry urged Pyongyang to abide by its non-nuclear commitment, saying the issue should be resolved in the framework of long-stalled, six-nation de-nuclearization talks.